Proteins, which participate in adhesion between a cell and an interstitial connective tissue and show various biological activities concerning the cell functions of animal cells, are called cell adhesive proteins. For example, there are known fibronectin, vitronectin, laminin, etc. It is known that the core sequence of the cell adhesion site of these proteins is arginine-glycine-aspartic acid [Arg--Gly--Asp] (hereinafter, occasionally referred to as RGD) [Pierschbachr, M. D., et al., Nature, 309, 30 (1984), Suzuki, S., et al., J. Biol. Chem., 259, 15307 (1984), Plow, E., et al., Proc. Natl. Acad. Sci. USA, 82, 8057 (1985)]. The RGD interacts with a receptor of a cell adhesive protein, and as a result, it shows various pharmacological activities.
For example, fibrinogen being present in plasma interacts with a platelet membrane glycoprotein complex IIb/IIIa via RGD to cause a platelet aggregation, and it is considered that a synthetic peptide having RGD inhibits the interaction between fibrinogen and a platelet membrane glycoprotein complex IIb/IIIa and hence, it is useful as a platelet aggregation inhibitor [Phillips, D. R., Cell, 65, 359 (1991)]. Besides, it is also known that a peptide having a RGD derived from snake venom effectively inhibits bone resorption by osteoclast [Sato, M., et al., J. Cell Biol., 111, 1713 (1990)].
Besides, fibronectin is considered to participate in differentiation and growth of cells [Yamada, K. M., et al., Ann. Rev. Biochem., 52, 761 (1983)], but since it stimulates migration of fibroblast and macrophage, it is expected to be applied to the treatment of wound or the regulation of immune mechanism. Particularly, fibronectin has been tried in the local treatment of corneal disorders by utilizing the promotion effect thereof on wound healing [Fujikawa, L. S., et al., Lab. Invest., 45, 120 (1981)].
Moreover, cell adhesive proteins have been drawing attention as a substance participating in cancer metastasis. A cancer cell forms a multicellular mass in the presence of fibronectin or laminin so that it can more easily grow or survive. In fact, it has been confirmed that an RGD sequence, which is an adhesive core of fibronectin, inhibits the metastasis of cancer cell [Humphries, M. J. et al., Science, 233, 467 (1986)].
Thus, since cell adhesive proteins show various biological activities, a medicament which can selectively interact with a receptor of these proteins can be expected to be useful in the prophylaxis or treatment of various diseases.
On the other hand, a lot of screening on non-peptide compounds interacting with a receptor of these proteins has been as reported, for example, in EP 512831, EP 540334, WO 94/8962, WO 94/12181, EP 445796, etc. However, there is no compound which can clinically be used.
Under these circumstances, it has been desired to develop a platelet aggregation inhibitor, a cancer metastasis inhibitor, a wound healing agent or a bone resorption inhibitor, which selectively interacts with a receptor of a cell adhesive protein such as fibrinogen, fibronectin, etc., and shows excellent absorbability and excellent stability in living body.